JP5374366B2 - Cochlear implant power supply system and method - Google Patents

Description

  The present invention relates to a cochlear implant, and more particularly to a power supply system and method for a cochlear implant.

  Cochlear implants and other cochlear implant devices are one option for helping people with severe hearing impairment or severe hearing impairment. Unlike conventional hearing aids that only apply an amplified modulated audio signal, the cochlear implant is based on direct electrical stimulation of the auditory nerve. Typically, a cochlear implant electrically stimulates the neural structures within the inner ear so that a hearing that is most similar to normal hearing is obtained.

  More specifically, a normal ear transmits audio to the eardrum 102 via the outer ear 101, as shown in FIG. 1, which stimulates the cochlea 104 by moving the bones of the middle ear 103. The cochlea 104 includes an upper path known as the vestibular floor 105 and a lower path known as the tympanic floor 106, which are connected by a cochlea pipe 107. In response to the received sound transmitted by the middle ear 103, the vestibular floor 105 and the tympanic floor 106 filled with liquid function as vibrators that transmit waves and generate electrical pulses, which are transmitted to the cochlear nerve 113. Finally reach the brain.

  There are people who have partially or completely lost normal sensory hearing. Cochlear implant systems have been developed that overcome this by directly stimulating the user's cochlea 104. A typical artificial cochlear device essentially comprises two parts (sound processor and implantable stimulator 108). A sound processing device (not shown in FIG. 1) typically includes a microphone, a power supply (battery) for the entire system, and a processing device used to perform signal processing of acoustic signals and extract stimulation parameters. Including. In the latest artificial devices, the sound processing device is an ear-hook type (BTE) device. The stimulator generates stimulation patterns and guides them to neural tissue by means of an electrode array 110 that is usually placed on the tympanic floor in the inner ear. The connection between the sound processing device and the stimulator is usually established by a radio wave (RF) link. Note that both stimulation energy and stimulation information are transmitted via the RF link. Typically, digital data transfer protocols that employ a bit rate of several hundred kilobits per second are used.

  Examples of standard stimulation methods for cochlear implants include B.I. There is what is called “Continuous-Interleaved-Sampling Strategies” (CIS) developed by Wilson (see, for example, Non-Patent Document 1 incorporated herein by reference in its entirety).

  The total power balance of current artificial cochleas using RF links is essentially:

によって表され、ここで、Ｐ_ＢＡＴＴは、バッテリによって出力される電力であり、Ｐ_ＳＩＧは、（外部）信号処理の消費電力であり、Ｐ_ＳＴＩＭは、インプラント式刺激装置の消費電力（実際の電気的刺激力を含む）を表し、ηは、ＲＦリンクの総電力効率である。

Where P _BATT is the power output by the battery, P _SIG is the power consumption of (external) signal processing, and P _STIM is the power consumption of the implantable stimulator (actual power Η is the total power efficiency of the RF link.

の比は、ＲＦ送信器に流れる電力を表す。なお、使用する刺激法に応じてＰ_ＳＴＩＭおよびＰ_ＳＩＧが最初に決定される。例えば、上記のＣＩＳ法については、標準値は、Ｐ_ＳＴＩＭ＝６ｍＷおよびＰ_ＳＩＧ＝６ｍＷである。η＝０.２５の場合、Ｐ_ＢＡＴＴ＝３０ｍＷである。

The ratio of represents the power flowing to the RF transmitter. Note that P _STIM and P _SIG are first determined according to the stimulation method used. For example, for the above CIS method, the standard values are P _STIM = 6 mW and P _SIG = 6 mW. When η = 0.25, P _BATT = 30 mW.

(Totally Implantable Cochlear Implant (TICI))
A fully implantable cochlear implant (TICI) is a cochlear implant system that does not have external elements that are permanently used. The TICI typically includes a microphone, and in the subsequent stage, audio signal processing for performing a specific stimulation method (for example, CIS) is performed. Also included are stimulation electrodes, power management electronics, and coils for transcutaneous transmission of RF signals.

  Unlike pacemaker implants, TICI power supplies are generally not stable with non-rechargeable batteries. This is because the total pulse repetition rate of TICI is much higher. For example, a pacemaker generates about 1 pulse per second, whereas a cochlear implant using CIS typically generates about 20 kilopulses per second. In addition, pacemakers perform simple detection tasks, whereas cochlear implants typically perform complex audio signal processing. As a result, TICI typically requires a rechargeable battery that needs to be charged after a predetermined operating time. External devices used for charging include devices that transmit RF signals transcutaneously. This may be wearable and may include a prechargeable battery and other auxiliary devices as required, including but not limited to remote controls and FM appliances.

(Rapid charging)
Traditionally, implantable rechargeable batteries are charged via inductive RF links. A standard approach called “rapid charge” is limited only by the maximum charge current, but requires that the battery be charged as fast as possible. In typical modern battery technology (eg, 3.6V lithium ion technology), the absolute maximum charging current in mA is nominally equal to the capacity C. For example, in a battery with a capacity C = 20 mAh, the absolute maximum charging current is 20 mA, so it takes about 1 hour to charge an empty battery. However, the following aspects of rapid charging need to be considered.

  (A) Typical fast charging (ie, slowly discharging to the lower limit of energy over a long period of time and then charging to the upper limit of energy at a maximum charging current in a relatively short time) puts considerable pressure on the battery. In some cases, the number of charge cycles is reduced before the battery capacity runs out. Such schemes typically provide only 500-1000 cycles for lithium ion technology. When the battery capacity is sufficient to operate the TICI for one day, the charging operation required for one day is one time. A maximum of 1000 cycles means that TICI or at least the rechargeable battery for TICI may have to be replaced after 3 years of implantation. However, it can be impractical for various cochlear implant applications if it only has a period of at most 3 years.

  (B) The battery life can be extended without increasing the maximum number of charge cycles by increasing the capacity. For example, if the capacity is large enough to operate the TICI for 5 days instead of just 1 day, the maximum battery life is also extended to about 15 years, which is considered acceptable. However, increasing the volume by a factor of 5 also increases the volume to volume by the same amount, which may not be possible in that the space within the cochlear implant is very limited. Although the approach of placing an implantable rechargeable battery elsewhere in the body rather than locally near the inner ear is technically possible, it is not currently practiced. For example, it would make sense from a technical point of view to place a rechargeable battery in place on the pacemaker device in the upper chest.

  (C) Rapid charging may increase the temperature of the battery, and the temperature of the surrounding tissue may increase accordingly. The amount of temperature rise may depend on many factors including RF field strength, charging current, charging time, TICI mass, and blood circulation. A maximum temperature rise of 1K is acceptable.

  (D) In the case of the latest battery technology, the maximum capacity of the rechargeable battery locally disposed in the vicinity of the ear is limited to about several tens mAh. This limitation is due to spatial requirements and allows TICI to operate for about a day. However, from the patient's point of view, frequent charging every day for at least one or two hours is not an attractive option.

(Consideration of other rechargeable batteries)
Implantable rechargeable batteries may not be appropriate under certain circumstances. For example, for a very young child, an implantable rechargeable battery may be too large or too heavy. For many patients, carrying a power supply to the head or a somewhat cumbersome (daily) charging action would not be a pleasure.

Wilson BS, Finley CC, Lawson DT, Wolf RD, Eddington DK, Rabinowitz WM, “Better speech recognition with cochlear implants”, Nature, vol. 352, 236-238, July 1991

  According to a first embodiment of the present invention, a cochlear implant system has an implantable part including a stimulation module that generates an electrical stimulation signal representing an acoustic signal to the user's auditory system. The implantable portion further includes a battery that powers the stimulation module, a receiving module that receives a power signal across the user's skin, and a charging module that charges the battery using the power signal. The charging module charges the battery below the maximum charging rate.

  In a related embodiment of the invention, the cochlear implant system may further include an outer portion adapted for placement at a particular location on the user's outer skin. The outer portion includes a power signal transmission module that transmits a power signal across the user's skin and a second battery that powers the power signal transmission module. The second battery may be rechargeable. The outer portion is contained within a single housing and includes a first magnet, the implantable portion includes a second magnet, and the outer portion substantially includes a magnetic force between the first magnet and the second magnet. May be adapted to be held in an appropriate position by the user. Alternatively, or in combination with magnetic force, the outer portion may be held in place using other mechanisms known in the art such as ear hooks.

  In further related embodiments of the present invention, the power signal may not include modulation programming data or may be low rate modulation programming data. The charging module may charge the battery at less than 50% or less than 10% of the maximum charge rate. The battery may supply power to the stimulation module when a power signal is not received by the receiving module. The battery may supply power to the stimulation module while the charging module charges the battery. The stimulation module may be adapted to be powered by a power signal when the battery is not operating. The stimulation module may include an electrode array, a microphone that receives an acoustic signal, and a signal processor that converts the acoustic signal received by the microphone into an electrical stimulation signal representing the acoustic signal. The signal processor stimulates the electrode array with an electrical stimulation signal. The receiving module may include a receiving coil that receives the power signal.

  In another embodiment of the invention, the cochlear implant system includes an outer portion that is adapted for placement in a particular location on the user's outer skin. The outer portion includes a power signal transmission module that transmits a power signal across the user's skin. The outer portion further includes a battery that powers the power signal transmission module. The implantable portion receives the power signal and generates an electrical stimulation signal that represents an acoustic signal to the user's auditory system. The implantable part does not have a battery.

  In related embodiments of the invention, the battery may be rechargeable. The outer portion may be contained within a single housing and include a first magnet and the implantable portion may include a second magnet. The outer portion is adapted to be held in place by the user based on the magnetic force between the first magnet and the second magnet. The power signal may not include modulation programming data or may include low rate modulation programming data.

  In yet a further related embodiment of the invention, the implantable portion comprises an electrode array, a microphone that receives the acoustic signal, and a signal processor that converts the acoustic signal received by the microphone into an electrical stimulation signal representative of the acoustic signal. May be included. The signal processor stimulates the electrode array with an electrical stimulation signal. The implantable portion may include a receiving coil that receives a power signal, and the outer portion includes a magnet that secures the outer portion in a position adjacent to the receiving coil.

  In another embodiment of the present invention, a method for operating a cochlear implant system is provided. The method includes receiving a power signal by the implant portion, the implantable portion including a battery having a maximum charge rate. The battery is charged below the maximum charge rate using the power signal.

  In a related embodiment of the invention, the power signal may be transmitted across the user's skin to the implant. The power signal may not include modulation programming data or may include low rate modulation programming data.

  In further embodiments of the present invention, an outer portion may be provided that is adapted for placement in a particular location on the user's skin. The outer portion may include a power signal transmission module that transmits a power signal across the user's skin to the implant portion and a second battery that powers the power signal transmission module. The method may further include charging the second battery. The outer portion may be contained within a single housing and may include a first magnet and the implantable portion may include a second magnet. The outer portion may be held in an appropriate position by the user based substantially on the magnetic force between the first magnet and the second magnet.

  In still further embodiments of the present invention, charging the battery may include charging the battery at less than 50% or 10% of the maximum charge rate. If the power signal is not received by the implant part, the battery may be used to power the implantable part. The power signal may be used to simultaneously charge the battery and provide operating power to the implantable portion for stimulating the user's auditory system. Charging the battery may consume less power than providing operating power. A power signal may be used to supply power to the implantable portion when the battery is not operating. The implantable portion may generate an electrical stimulation signal that represents an acoustic signal. The implantable portion includes an electrode array, a microphone, and a signal processor, wherein the method converts an acoustic signal received by the microphone into an electrical stimulation signal representing the acoustic signal in the signal processor, Stimulating with an electrical stimulation signal may further be included. The implantable portion includes a receiving coil that receives a power signal, the outer portion includes a magnet, and the method may further include using the magnet to secure the outer portion in a position adjacent to the receiving coil. .

  In another embodiment of the present invention, a method of operating a cochlear implant includes providing an outer portion that is adapted for placement in a particular location on a user's outer skin. The outer portion includes a power signal transmission module that transmits a power signal across the user's skin and a first battery that powers the power signal transmission module. The power signal is received by an implant unit that does not have a battery. The implant unit generates an electrical stimulation signal that represents an acoustic signal.

  In related embodiments of the invention, the power signal may not include modulation programming data or may include low rate modulation programming data. The implantable portion may include an electrode array, a microphone, and a signal processor. The signal processor converts the acoustic signal received by the microphone into an electrical stimulation signal representing the acoustic signal, and stimulates the electrode array with the electrical stimulation signal. The implantable portion may include a receiving coil that receives a power signal and the outer portion may include a magnet. You may fix an outer part to the position adjacent to a receiving coil using a magnet. The battery may be rechargeable. The outer portion may be contained within a single housing and include a first magnet and the implantable portion may include a second magnet. The outer portion is held in an appropriate position by the user based on the magnetic force between the first magnet and the second magnet.

  In another embodiment of the invention, the cochlear implant system includes an outer portion that is adapted for placement in a particular location on the user's outer skin. The outer portion includes a first magnet and a power signal transmission module that transmits a power signal across the user's skin to the implantable portion. The implantable part has a second magnet. The outer portion further includes a battery that powers the power signal transmission module. The outer portion is housed within a single housing and is adapted to be held in an appropriate position by the user based substantially on the magnetic force between the first magnet and the second magnet.

  In related embodiments of the invention, the battery may be rechargeable. The power signal may not include modulation programming data.

The foregoing features of the invention will be more readily understood by reference to the following detailed description, taken in conjunction with the accompanying drawings, in which:
The present invention further provides, for example:
(Item 1)
A cochlear implant system,
A stimulation module that generates an electrical stimulation signal representing an acoustic signal to the user's auditory system;
A battery for powering the stimulation module, the battery having a maximum charge rate;
A receiving module for receiving a power signal across the user's skin;
A charging module for charging the battery at less than the maximum charging rate using the power signal;
A cochlear implant system comprising an implantable portion.
(Item 2)
Further comprising an outer portion adapted for placement in a specific location of the user's hull,
The outer part is
A power signal transmission module for transmitting the power signal across the skin of the user;
A second battery for supplying power to the power signal transmission module;
The cochlear implant system according to item 1, comprising:
(Item 3)
The cochlear implant system according to item 2, wherein the second battery is rechargeable.
(Item 4)
The outer portion is contained within a single housing, the outer portion includes a first magnet, the implantable portion includes a second magnet, and the outer portion substantially includes the first magnet and the Item 5. The cochlear implant system of item 2, adapted to be held in an appropriate position of the user based on a magnetic force between the second magnet.
(Item 5)
The outer portion is housed in a single housing, the outer portion includes a first magnet, the implantable portion includes a second magnet, and the outer portion is adapted to the user's appropriateness using an ear hook. The cochlear implant system according to item 2, adapted to be held in position.
(Item 6)
The cochlear implant system according to item 1, wherein the power signal does not include modulation programming data.
(Item 7)
The cochlear implant system according to item 1, wherein the power signal includes low rate modulation programming data.
(Item 8)
The cochlear implant system according to item 1, wherein the charging module charges the battery at less than 50% of the maximum charging rate.
(Item 9)
The cochlear implant system according to item 1, wherein the charging module charges the battery at less than 10% of the maximum charging rate.
(Item 10)
The cochlear implant system according to item 1, wherein the battery supplies power to the stimulation module when the power signal is not received by the receiving module.
(Item 11)
The cochlear implant system according to item 1, wherein the battery supplies power to the stimulation module while the charging module charges the battery.
(Item 12)
The cochlear implant system according to item 1, wherein the stimulation module is adapted to be powered by the power signal when the battery is not operating.
(Item 13)
The stimulation module includes:
An electrode array;
A microphone for receiving an acoustic signal;
A signal processor for converting an acoustic signal received by the microphone into an electrical stimulation signal representing the acoustic signal, the signal processor stimulating the electrode array with the electrical stimulation signal;
The cochlear implant system according to item 1, comprising:
(Item 14)
The cochlear implant system according to item 1, wherein the receiving module includes a receiving coil that receives the power signal.
(Item 15)
An outer portion adapted for placement in a specific location on the user's skin,
A power signal transmission module that transmits a power signal across the skin of the user;
A battery for supplying power to the power signal transmission module;
Including an outer portion, and
An implantable portion that receives the power signal and generates an electrical stimulation signal representing an acoustic signal to the user's auditory system, the implantable portion having no battery;
A cochlear implant system comprising:
(Item 16)
16. The cochlear implant system according to item 15, wherein the battery is rechargeable.
(Item 17)
The outer portion is contained within a single housing, the outer portion includes a first magnet, the implantable portion includes a second magnet, and the outer portion includes the first magnet and the second magnet. 16. The cochlear implant system according to item 15, adapted to be held in an appropriate position of the user based on the magnetic force between the magnets.
(Item 18)
16. The cochlear implant system according to item 15, wherein the power signal does not include modulation programming data.
(Item 19)
16. The cochlear implant system according to item 15, wherein the power signal includes low rate modulation programming data.
(Item 20)
The implantable part is
An electrode array;
A microphone for receiving an acoustic signal;
A signal processor for converting an acoustic signal received by the microphone into an electrical stimulation signal representing the acoustic signal, the signal processor stimulating the electrode array with the electrical stimulation signal;
The cochlear implant system according to item 15, comprising:
(Item 21)
16. The cochlear implant system according to item 15, wherein the implantable portion includes a receiving coil that receives the power signal, and the outer portion includes a magnet that secures the outer portion in a position adjacent to the receiving coil.
(Item 22)
A method of operating a cochlear implant system comprising:
Receiving a power signal by the implant portion, the implantable portion including a battery having a maximum charge rate;
Charging the battery below the maximum charge rate using the power signal;
Including the method.
(Item 23)
24. The method of item 22, further comprising transmitting the power signal across the user's skin to the implant portion.
(Item 24)
24. The method of item 23, wherein the power signal does not include modulation programming data.
(Item 25)
24. The method of item 23, wherein the power signal comprises low rate modulation programming data.
(Item 26)
Further comprising providing an outer portion adapted for placement in a particular location of the user's hull;
The outer part is
A power signal transmission module for transmitting the power signal to the implant portion across the skin of the user;
A second battery for supplying power to the power signal transmission module;
24. The method according to item 23, comprising:
(Item 27)
27. A method according to item 26, further comprising charging the second battery.
(Item 28)
The outer portion is housed in a single housing, the outer portion includes a first magnet, the implantable portion includes a second magnet, substantially the first magnet and the second magnet. 27. The method of item 26, further comprising holding the outer portion in an appropriate position for the user based on the magnetic force between the user and the user.
(Item 29)
24. The method of item 22, wherein charging the battery comprises charging the battery at less than 50% of the maximum charge rate.
(Item 30)
24. The method of item 22, wherein charging the battery includes charging the battery at less than 10% of the maximum charge rate.
(Item 31)
24. The method of item 22, further comprising supplying power to the implantable portion using the battery if the power signal is not received by the implant portion.
(Item 32)
23. The method of item 22, further comprising simultaneously providing operating power to the implantable portion to charge the battery using the power signal to stimulate the user's auditory system.
(Item 33)
33. A method according to item 32, wherein charging the battery consumes less power than providing operating power.
(Item 34)
23. The method of item 22, further comprising powering the implantable portion using the power signal when the battery is not operating.
(Item 35)
24. The method of item 22, further comprising generating an electrical stimulation signal representative of an acoustic signal by the implantable portion.
(Item 36)
The implantable portion includes an electrode array, a microphone, and a signal processor;
23. The item 22, further comprising: converting the acoustic signal received by the microphone into an electrical stimulation signal representing the acoustic signal and stimulating the electrode array with the electrical stimulation signal in the signal processor. Method.
(Item 37)
The implantable portion includes a receiving coil for receiving the power signal, the outer portion includes a magnet, and further includes fixing the outer portion in a position adjacent to the receiving coil using the magnet. 23. The method according to 22.
(Item 38)
A method of operating a cochlear implant, the method comprising:
Providing an outer portion adapted for placement in a particular location of the user's hull, the outer portion comprising:
A power signal transmission module that transmits a power signal across the skin of the user;
A first battery for supplying power to the power signal transmission module;
Including, and
Receiving the power signal at an implant portion, wherein the implantable portion does not include a battery;
Generating an electrical stimulation signal representing an acoustic signal by the implant portion;
Including a method.
(Item 39)
40. The method of item 38, wherein the power signal does not include modulation programming data.
(Item 40)
40. The method of item 38, wherein the power signal comprises low rate modulation programming data.
(Item 41)
The implantable portion includes an electrode array, a microphone, and a signal processor;
39. The item 38, further comprising converting an acoustic signal received by the microphone into an electrical stimulation signal representative of the acoustic signal and stimulating the electrode array with the electrical stimulation signal in the signal processor. Method.
(Item 42)
The implantable portion includes a receiving coil for receiving the power signal, the outer portion includes a magnet, and further includes fixing the outer portion in a position adjacent to the receiving coil using the magnet. 38. The method according to 38.
(Item 43)
39. A method according to item 38, further comprising charging the battery.
(Item 44)
The outer portion is contained within a single housing, the outer portion includes a first magnet, the implantable portion includes a second magnet, and between the first magnet and the second magnet. 39. The method of item 38, further comprising holding the outer portion in a proper position of the user based on the magnetic force of the user.
(Item 45)
An outer portion adapted for placement in a specific location on the user's skin,
A first magnet;
A power signal transmission module for transmitting the power signal across the user's skin to an implantable portion, the implantable portion having a second battery; and
A battery for supplying power to the power signal transmission module;
A cochlear implant system comprising an outer portion, comprising:
The outer portion is housed in a single housing so that the outer portion is held in place by the user substantially based on the magnetic force between the first magnet and the second magnet. Adapted to the system.
(Item 46)
46. A cochlear implant system according to item 45, wherein the battery is rechargeable.
(Item 47)
46. A cochlear implant system according to item 45, wherein the power signal does not include modulation programming data.

FIG. 1 shows the ear structure of a human ear and a typical cochlear implant system. FIG. 2 is a block diagram illustrating a cochlear implant system that implements “background charging” in accordance with one embodiment of the present invention.

  In an exemplary embodiment of the invention, a system and method for operating a cochlear implant includes external elements including a battery and a power transfer module. The implant element receives a power signal from the power transfer module and uses it to power the implant element while simultaneously charging the implantable rechargeable battery in its background. A further embodiment of the present invention relates to a small “battery button” that can be advantageously used to power an implant cochlear element but does not provide modulation programming data.

"Background charging"
FIG. 2 is a block diagram illustrating a cochlear implant system that performs “background charging” in accordance with one embodiment of the present invention. “Background charging” can be used, for example, to charge a fully implantable cochlear implant (TICI). The external device 201 may be button-shaped (“battery button”) and includes an external battery 203 along with the RF circuit 204 and the transmission coil 205 for generating and transmitting the power signal transmission coil 205. The external device 201 also includes a magnet 206, which in combination with the second implant magnet 207 keeps the transmit coil 205 and the receive coil 208 at a minimum distance. The external battery may be rechargeable.

  In many embodiments, the external device 201 transmits power to the TICI but does not transmit information or transmits minimal information. Minimal information includes, for example, low rate programming data that is modulated into a power signal. As used herein and in the appended claims, the term “low rate programming data” shall mean data transmitted at a rate of 1 kHz or less, unless the context requires otherwise.

The energy received at the TICI 202 (eg, by the receiving module 208 illustrated as a coil) can be split into two parts. The first portion of energy provides TICI 202 with sufficient energy P _SIG + P _STIM for normal operation, ie, sufficient for the generation of a stimulation signal that stimulates electrode 212 by signal processing 210 and stimulation module 211. Can be used to The second portion of energy P _RECHARGE is used by the charging module 213 to charge the energy storage device 209. Since P _RECHARGE is typically much smaller than P _SIG + P _STIM , this concept is called “background charging”.

  The total energy balance is

によって求められる。

Sought by.

The main difference from equation (1) is that the RF efficiency η _cw can be substantially higher than η because only the CW signal is used without using data. For example,
When P _BATT = 30 mW, η _cw = 0.5, P _STIM = 6 mW, and P _SIG = 6 mW, P _RECHARGE = 3 mW.

When background charging is employed, re-storage of the TICI battery 209 is performed relatively slowly. However, depending on the instantaneous power storage state of the TICI battery 209, the operation can be performed without using the external device 201. The background charging period T _RECHARGE and the TICI operation period T _OP without using the external device 201 (that is, when energy is supplied to the TICI 202 from the internal energy storage device)
T _RECHARGE P _RECHARGE = T _OP (P _SIG + P _STIM ) (3)
Given by.

This is effective when the energy amount T _RECHARGE P _RECHARGE is not limited by the capacity of the battery for TICI. In the above example, from equation (3)

が得られる。

Is obtained.

  Some aspects of background charging are summarized below.

  (A) Using an external device worn by the user to slowly charge the rechargeable battery 209 is somewhat inconsistent with a fully implantable system. However, the difference between background charging and rapid charging is simply a quantity difference, not a quality difference. Of course, even if an external battery is not used, power can be supplied to the stimulation module as long as the battery is fully charged.

  (B) Rapid charging and background charging are not mutually exclusive. The implantable stimulator may be designed so that both charging techniques are practically realized.

  (C) Compared with rapid charging, background charging inevitably stops charging.

  (D) External devices used for background charging (ie, battery buttons) can be designed to maximize patient comfort. The components of the external device may be concentrated in a single housing that is approximately the same size as the RF transmitter used in current cochlear implant systems. In many embodiments, the external system may not be provided with wiring.

  (E) For background charging, the problem of battery cycle life is greatly mitigated. There are two reasons for this. First, since the charging current is low, the degree of stress related to battery charging is significantly reduced. Charging is performed below the maximum charging rate of the battery. For example, a battery can be charged at 75%, 50%, 25%, or 10% of its maximum charge rate, but is not limited thereto. Second, because of the long charging time, the cycle period is “naturally” much longer than that of fast charging.

  (F) Problems related to temperature changes are minimized.

  (G) Background charging can be reasonably implemented for battery capacities C of almost all sizes. For example, the patient is very pleased even with a relatively small capacity that can operate the TICI only for about an hour without using external equipment.

  (H) With regard to background charging, there is an exception in TICI where there is no implantable rechargeable battery (C → 0) but there are other (less effective) means for storing electrical energy instead. It is. For example, a capacitor typically used to stabilize the implant supply voltage can be considered an energy storage device. The power supply power necessary for the operation of TICI must be supplied by an external (chargeable) battery. For example, for very young children it may be appropriate not to include an implantable rechargeable battery when a very small implant is required. In addition, for many patients, the idea of carrying a power supply in the head is not desirable, and the somewhat cumbersome (daily) charging action may not be pleasing.

  (I) It may be advantageous to use an external battery with TICI if the implantable battery is not functioning (eg, after the service life has passed) and the implant is not performed again. In such cases, an external battery (ie, a “button battery”) may be used to power the stimulation module directly without using an implantable battery.

(J) One advantage inherent in background charging is related to the overall energy status of TICI. During the charging period, substantially constant energy flows with respect to TICI (see equation (2)). Within TICI, but power consumption is less constant by the signal processing _{P SIG,} stimulation force _{P STIM} (e.g., depending on the volume level) varies as a function of time. A power management system may be designed that aims to keep the sum of P _STIM + P _RECHARGE constant. Thus, the battery functions as an energy buffer system. For example, if P _STIM only has 20% of maximum consumption at a particular moment, the remaining 80% can be used to charge the battery without wasting.

  (K) In many embodiments, the battery button typically generates a continuous wave (CW) signal. Since there is no data modulated on the transmitted energy, the external device 201 is conveniently simpler and less expensive than external devices of other cochlear implant systems. This is especially important for children.

  (L) In many embodiments, the button 201 is maintained in place with only magnetic force (ie, magnetic force between magnets 206 and 207) without applying excessively irritating pressure to the skin. You may make it lightweight enough. Alternatively, or in addition to magnetic force, other mechanisms such as ear hooks may be used to keep the button in place. In a preferred embodiment, the weight of the button is approximately less than 10-12 g.

  (M) Since battery buttons can be manufactured relatively inexpensively, several can be supplied for one implant.

  (N) Since the buttons can be easily replaced, it is generally not necessary to provide energy throughout the day by the button's external battery. Several can be provided for one implant system because they can be made relatively inexpensively.

  While various exemplary embodiments of the invention have been disclosed, those skilled in the art will recognize that various changes and modifications can be made to achieve some of the advantages of the invention without departing from the precise scope of the invention. It is obvious.

Claims (13)

A cochlear implant system comprising an implantable portion and an outer portion ,
The implantable part is
A stimulation module that generates an electrical stimulation signal representing an acoustic signal to the user's auditory system;
A battery for supplying power to the stimulation module, the battery has a maximum charge rate, a battery,
A receiving module for receiving a power signal across the user's skin;
Look including a charging module for charging the battery in less than said maximum charging rate with said power signal,
The outer portion is adapted to be placed at a specific location on the user's hull;
The outer part is
A power signal transmission module for transmitting the power signal across a user's skin, wherein the power signal does not include modulated data; and
A second battery for supplying power to the power signal transmission module;
Including a cochlear implant system. The second battery can be charged, cochlear implant system of claim 1. Said outer portion is accommodated in a single housing, the outer portion includes a first magnet, the implantable portion includes a second magnet, the outer portion is first force to Ru adapted Tei to be held in place of the substantially based user, cochlear implant system of claim 1 between the magnet and the second magnet. The outer portion is housed in a single housing , the outer portion includes a first magnet, the implantable portion includes a second magnet, and the outer portion includes an ear hook. Ru Tei is adapted to be held in place of the user using, cochlear implant system of claim 1. The charging module charges the battery in less than 50% of the maximum charging rate, cochlear implant system of claim 1. The charging module charges the battery in less than 10% of the maximum charging rate, cochlear implant system of claim 1. The battery, the supply power to the stimulation module when the power signal is not received by the receiving module, cochlear implant system of claim 1. The charging module, while the battery is supplying power to the stimulation module to charge the battery, cochlear implant system of claim 1. The stimulation module, wherein when the battery is not operating, Ru adapted Tei to the supplied to the power signal thus power, cochlear implant system of claim 1. The stimulation module includes:
An electrode array;
A microphone for receiving an acoustic signal;
Acoustic signals thus received to the microphone, a signal processor for converting the electrical stimulation signal representative of the acoustic signal, and a signal processor for stimulated with electrical stimulation signals to the electrode array, wherein Item 8. The cochlear implant system according to Item 1. It said receiving module comprises a reception coil for receiving the power signal, a cochlear implant system of claim 1. A cochlear implant system comprising an outer portion adapted to be placed at a specific location on a user's outer skin ,
The outer part is
A first magnet;
A power signal transmission module for transmitting a power signal across the user's skin to an implantable portion , the power signal not including modulated data, wherein the implantable portion includes a second magnet Having a power signal transmission module;
Look including a battery for supplying power to said power signal transmission module,
Outer part is accommodated in a single housing, the outer portion is in position of the user substantially based on the magnetic force between the first magnet and the second magnet Tei Ru, cochlear implant system is adapted to be held. The battery is rechargeable, cochlear implant system of claim 12.

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